Continuous facsimile scanner



July l0, 1945. I J. v. L.. HOGAN 2,379,906"` I CONTINUOUSF'ACSIMILE SCANNER Filed Nov. 22, 1941 Patented July 120, 1945 l UNITED s'rli'rls,Y

2,375,906 f l f CONTINUOUS FAcSlMrLE SCANNER y l John V. L. Hogan, Forest Hills, N.` Y.,v assignorfto` l Faximile, Inc., New York, N. Y., a corporation` l of Delaware l Application Ncvemberzalen, senarnaizo 1 claim.. (otite-4125i The present invention `concerns facsimile scanners.

One object of the present invention `is to provide an improved facsimile pick-up'scanner.

A further object is to provide a facsimile pickup scanner having greaterv signal-to-noise ratio than scanners hitherto available.

A still further object is to provide a simple and cheap pick-up scanner having great sensitivity and high signal-to-noise ratio.

Still another object is to provide a pick-up scanner capable of operating at high speed.

A particular object is to provide a simple pickup scanner for scanning a continuous sheet.

These and other objects will be apparent from the detailed description of the inventiongiven in connection with thedrawing.

In the drawing is shown one form of the present invention.

Fig. 1 shows a view of one form of the invention in perspective, and Fig. 2 shows a side view of the same form of the invention.

In order to transmit a facsimile by wire or radio it is first necessary to scan the copy to be transmitted and by means of the scanning process to generate signals representing the variations in density of the various parts of the copy. One method of generating these signals is to scan the copy with a spot of light reecting from the copy into a photo-electric cell. Single small pieces of copy may be scanned by attaching them to the surface of a drum which is rotated at a predetermined rate. This provides one dimension of the scanning while the other dimension may be provided by moving the drum along its axis or by moving the light source and photo-electric cell the modulated signals;` pick `up the radiated signals on` af receiving system: and lafter .ampliiicae tion-and rectiiication in the receiver, to operate l the recording member in arhelical ,facsimile rei cordel. Y n g `Fig, 1 shows lin perspective one form` ofthe present inventlonwhere22 isalong sheetofcopy to betransmitted," I4 is a linear light source and 6 is alinear screen photo-electric mosaic andelec` tronbeam scanner constitutingan -iconoscope ln detail; a power supply and sweep voltage` generator 3, suppliedwith` power over wires 4 and 5 supplies` electron' stream` generating and sweep voltages to the iconoscope tube 5. Iconoscope tube 6 contains electron beam generating anddefleeting elements 36 for passing an electron stream across the long, narrow photo-electric mosaic l 1 for scanning a picture image thereon. Behind the linear mosaic 1` is located a pick-olf electrode 3 connected to amplifier Ii by means of lead 9..

The low sides of the power source 3` and amplifier from lamp I4 is focussed on the copy sheet 22 by along the drum. It is often desired to transmit uous sheet of copy is passed at a constant rate l under a linear light source. The light illuminates a line across the copy. The reilected light from the illuminated line is focussed on a. linear screen photo-electric mosaic. The signal is picked off of the mosaic by a sweeping electronic stream il are connected together by means of lead I0.

The amplified signals are fed to any suitable further device over leads VI2 and I3.

The image to be scanned may be illuminated in anysuitable manner as, for instance, by means of lamp I4 `having a long filament I5 supplied with electric` current over wires I B and'l'l. The light means of `lens I9. The line across the copy thus illuminated is focussed on mosaic 1 by means of;

the `width of a' line orcontinuously by means of motor 2 1 turning shaft 2l of drum 2ilth1'ua` suitable gear box 26. Ro1lers23 and 24 serve to keep copy sheet 22 in contact withdrum 20 to preventslipping of` the copy sheet 22 asit is drawn along by drum 2D. The contact arc should be suiiicient to properly drive `sheet 22 andhas 1 been shown as approximately 180 degrees, a1-

though not limited thereto.

Fig. 2 shows a side view ofthe same form of f the invention. The same parts of the device are and amplified. The ampliiied'signals. may be I \utilized in any of a number of conventional ways. `well known in the art. One way in which the signals may be utilized, for instance, is to mixV them with synchronizing; impulses generated at the end of each scanning line; modulate a radio..

designated by the samenumbers` as usedin Fig. 1. Fig. 2 shows in addition how the long" copy sheet 22 may beunwound from a roll onlv shaft 30 and rewound in a roll on shaft 3|. The roll ducedwhen either lamp I5 or iconoscope tube 6 tween plats 31 may also be used in place of, or

in addition to, aperture between plates 38 or the method described above.

Whilel ther present scanner is" particularly 1 adapted to operate with long sheets of copy, it will handle short pieces equally well. Clamps 39 mounted between rollers 23 and 24 will serve to keep a short piece of copy in contact with the driving drum, permitting practically any length sheet to be scanned at will. Rollers23 and 24 may be placed near together, one on each side of thescanning line, if desired, to handle short pieces of copy more readily.

' Since the high speed scanning is accomplished electrically, this scanner is capable of extremely high speed operation. The charge storing characteristics ofvmosaie l provide a high degree of sensitivity and a high signal to noise ratio in the system The simple and eflcient manner in which the system operates will be apparent to those skilled in the art. It will be apparent that any length of copy may behandled and that any 'width up to the length of drum 20 may be used. Copy which is narrower than drum 20 is long may be, scanned by decreasing the sweep amplitude on beam 35. A margin of any desired width may be provided by sweeping beam 35 beyond the edges of the image of copy on mosaic 1. It will be evident that the aspect ratio or the relative horizontal or vertical enlargement of the reproduction may be controlled by the relative speeds of the beam 35 and drum 20. Distortion, focus and shading" of the mosaic scanning may be corrected by means and methods well known in the art.

While only one form of the present invention has been shown and described, many modifications will be apparent to those skilled in the art within the spirit and scope of the invention, as

`set forth in the appended claim.

i vide an accurate scanning surface over at least a narrow strip extending across said sheet, means for rotating said drum at a substantially constant re te for advancing said sheet to provide one scanning dimension, means for evenly illuminating said narrow strip, an iconoscope having a long narrow signal generating screen, means for o ptically projecting said illuminated strip on said screen, means yforvscanning said yscreen with an electron beam along a longitudinal path` t0. provide the second scanning dimension, and means for utilizing the signals generated by said screen.

` JOHN v. L. Homin. 

